The present invention generally relates to variable transmission windows. More specifically, the present invention relates to control systems for controlling the transmission of variable transmission windows and to various constructions of variable transmission windows.
Variable transmittance light filters, such as electrochromic light filters, have been proposed for use in architectural windows, skylights, and in windows and sunroofs for automobiles. Such variable transmittance light filters reduce the transmittance of direct or reflected sun light during daytime through the window, while not reducing such transmittance during nighttime. Not only do such light filters reduce bothersome glare and ambient brightness, but they also reduce fading and generated heat caused by the transmission of sunlight through the window.
Variable transmission windows have not been widely accepted commercially for several reasons. First, they tend to be very expensive due to the cost of materials required for their construction, and their complex construction makes mass-production difficult. Additionally, electrochromic windows tend to have a lower life expectancy than conventional windows due to degradation of the electrochromic materials used in the windows. The combination of added cost and lower life expectancy have deterred many architects and builders from using electrochromic windows.
Recent advances have resulted in electrochromic windows that cost less and have higher life expectancies. Examples of such electrochromic windows are disclosed in commonly assigned U.S. patent application Ser. No. 09/626,714, entitled xe2x80x9cELECTROCHROMIC WINDOWS AND METHOD OF MANUFACTURING THE SAME,xe2x80x9d filed on the same day as this application. Perhaps because electrochromic windows had not previously been widely accepted commercially, little thought had been given to practical window constructions that enable power to be delivered to an electrochromic window element through conventional types of window frame assemblies. While electrochromic windows have been discussed in the prior art, the typical construction that is disclosed merely shows two or more wires extending from a window frame in which the electrochromic window elements are mounted. Such a construction does not allow for electrochromic window elements to be mounted in a window sash that moves relative to a stationary window frame, nor do such constructions allow for easy construction of such window assemblies or easy replacement of an electrochromic window element. In general, electrochromic window assemblies can be relatively heavy, as may conventional window assemblies. Thus, if the window installers must additionally handle dangling wires from a window assembly when attempting to install the window assembly in a building, an additional person may be required just to manage the wires as the windows are being installed. Further, once the wires are secured to a power source, replacement of the windows is more difficult.
The prior art also fails to address techniques for controlling the transmission of a plurality of such electrochromic windows in a building either independently or in various groupings. Therefore, there exists a need for an electrical control system for controlling the transmittance of a plurality of variable transmission windows in a building.
Accordingly, it is an aspect of the present invention to provide an electrical control system for controlling a plurality of variable transmittance windows. To achieve these and other aspects and advantages, the electrical control system of the present invention comprises a master control circuit for supplying control signals representing transmittance levels for the variable transmission windows, and a plurality of window control circuits coupled to each of the master control circuits. Each window control circuit controls the transmittance of at least one of the variable transmission windows in response to control signals received from the master control circuit.
Another aspect of the present invention is to provide a building comprising a plurality of variable transmission windows, a master control circuit for supplying control signals representing transmittance levels for the variable transmission windows, and a plurality of window control circuits coupled to the master control circuit. Each window control circuit controlling the transmittance of at least one of the variable transmission windows in response to control signals received from the master control circuit.
An additional aspect of the present invention is to provide a window control circuit for controlling at least one variable transmission window in response to signals received from a master control circuit. The window control circuit of the present invention comprises a micro controller coupled to receive the signals from the master control circuit, and a switching regulator circuit for supplying power to the at least one variable transmission window. The switching regulator circuit is coupled to the micro controller and is responsive to signals received from the micro controller to selectively vary the power supplied to the variable transmission window.
Another aspect of the present invention is to provide a master control circuit for supplying control signals to at least one window control circuit that controls the transmittance of at least one variable transmission window in response to the control signals. The master control circuit of the present invention comprises a micro controller for generating signals representing a desired transmittance for the variable transmission window and a power switching circuit for supplying power to the at least one window control circuit. The power switching circuit is coupled to the micro controller and is responsive to signals received from the micro controller to vary the power supplied to the at least one window control circuit.
An additional aspect of the invention is to provide an electrical control system for controlling the transmittance of at least one variable transmission window. The control system of the present invention comprises a control circuit coupled to the variable transmission window for selectively varying the electrical energy applied to the variable transmission window, and a receiver for receiving a command from a remote control device via a wireless communication link. The receiver is coupled to the control circuit to supply a control signal representing the received command. The control circuit responds to the receipt of a control signal by varying the transmittance of the variable transmission window.
Another aspect of the present invention is to provide an electrical control system for controlling the transmittance of at least one variable transmission window. The control system of the present invention comprises a control circuit coupled to the variable transmission window for selectively varying the electrical energy applied to the variable transmission window, a sensing circuit for sensing an abnormal electrical load condition including a near short or near open circuit, in the variable transmission window, and a security system interface coupled to receive an indication from the sensing circuit that an abnormal electrical condition exists in the variable transmission window.
Another aspect of the present invention pertains to a method of determining whether a security breach has occurred through the breakage or opening of a variable transmission window, the variable transmission window providing a current path when closed. The inventive method comprises the steps of sensing whether there is an electrical near short or near open circuit or other abnormal electrical performance indicative of physical damage to the window in the current path through the variable transmission window, and determining that there has been a security breach through the variable transmission window when an electrical near short or near open circuit or other abnormal condition is sensed.
An additional aspect of the present invention is to provide a window having a transmittance that varies in response to an electrical signal where the window comprises a window frame; a sash mounted to the window frame so as to be movable relative to the window frame; a variable transmission window element mounted in the sash; a first electrical coupler mounted to the window frame and electrically coupled to a source of an electrical signal; and a second electrical coupler mounted to the sash and electrically coupled to the variable transmission window element, the second electrical coupler moves relative to the first electrical coupler and contacts the first electrical coupler to thereby enable the electrical signal to be transmitted from the window frame to the variable transmission window element.
Another aspect of the present invention is to provide a window having a transmittance that varies in response to an electrical signal where the window comprises a window frame assembly; a variable transmission window element mounted in the window frame assembly; a first electrical coupler mounted to the window frame assembly and electrically coupled to a source of an electrical signal; and a second electrical coupler mounted to the variable transmission window element. The first electrical coupler includes a resilient contact member biased towards the second electrical coupler.
Yet another aspect of the present invention is to provide a window having a transmittance that varies in response to an electrical signal, where the window comprises: a window frame; a sash mounted to the window frame so as to be movable relative to the window frame; a variable transmission window element mounted in the sash; a first electrical coupler mounted to the window frame and electrically coupled to a source of an electrical signal; a second electrical coupler mounted to the sash and electrically coupled to the variable transmission window element; and a flexible cable coupled between the first and second electrical couplers to thereby enable the electrical signal to be transmitted from the window frame to the variable transmission window element, the flexible cable having a length sufficient to permit movement of the sash between open and closed positions.
Still another aspect of the present invention is to provide a window having a transmittance that varies in response to an electrical signal where the window comprises: a window frame; a variable transmission window element; a first electrical coupler mounted to the window frame and electrically coupled to a source of an electrical signal; and a second electrical coupler electrically coupled to the variable transmission window element. The first and second electrical couplers have contact surfaces that engage one another to thereby enable the electrical signal to be transmitted from the window frame to the variable transmission window element.